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7 May 6, 1947. F|$HER 2,420,128

COLLET CHUCK Filed Aug. 4, 1944 a Shee ts -Sheet 1 I n pen'ior (Isa/re E F/JA E/P- By. I

Attorney May 6, 1947.

G. FISHER COLLET CHUCK Filed Aug. 4, 1944 3 Sheets-Sheet 2 Inventor Attorney May 1947- G. FISHER COLLET CHUCK Filed Aug. 4, 1944 3 Sheets-Sheet 3 A ttdmey Patented May 6, 1947 -2,420,128 v ooLnE'r onto-K "George i i'slier, Leedsfiingland application August 4, 1944,:SeriatNoQ-548b2" 1 -'In-Great Britain ctober 8, \1943 e-oiaims.

invention relates to collet chucks more ;.particul arly {or-use; on machine tools and the lil e and hasfor'its-ehiefobjeetto provide a new on improved construction of collet chuck whereby an enhaneedegripcam be exerted upon the work held thereinand vprovideaphuck which is "easy to manufacture and eat the same time effective in operation. I v V Aocordingtothe invention the chuck is provided with two gripping collets or jaws one of which is fixdthe'lotlrer adjustable relatively thereto. By providing a fixed collet or jaw "the "correct positioning "and alignment of the work in the chuck is ensured "arfwtheadjustable collet jawnnamtains ltlie "workii'n- ?a 'Tfixed position relative to the fixed collet or jaw whose p0- -sition-- is known. v ln'gorde'rthat "the invention may be clearly tahessteou and readily carried -into effect the "same wnrncw be mofefully described "with"reference to and by the aid of the accompanying drawings, wherein:

Figure l is a front elevation of the chuck with the cover plate removed.

Figure 2 is a half sectional elevation of Figure 1.

Figure 3 is a rear elevation of Figure 1.

Figure 4 is a sectional elevation of a chuck with a modified form of draw mechanism.

Figure 5 is a diagrammatic View showing a chuck modified for multiple gripping.

Referring to the drawings, the chuck comprises a housing or body i which carries a pair of collet jaws 2, 3 one of which is fixed relative to the housing or body I. Each collet or jaw will be semi-circular on its outer surface or edge and will be ground in the bore and on the outside diameter. They will be held in pairs by cheese-head screws 4 and retained apart by suitable springs.

The adjustable collet or jaw 2 is radiused or inclined at 5 on its upper surface to provide a seating for the locking roller 6 carried by pins or studs 1 on the locking levers 8. Alternatively a slipper (not shown) may be inserted between the adjustable collet or jaw 2 and the locking roller 6 so that the roller does not bear directly upon the collet 2 with the result that the latter need not be radiused or inclined. The locking 1evers 8 operate on the second principle of levers wherein the fulcrum 9 is at one end of each lever and the load is adjacent thereto at H) between the fulcrum and the operating point I l. Preferably the locking levers 8 are made in two halves, the points ID at which the locking load isfappliedbeing (on each'sideofthe .collet and -'to fiet 'the lver's'iil are"archedito pass arouhdiithe collet- The ;6ther ends 0f the levers Qajfidr'ding the fulcrum'js are-provided with"studs 5 .12 engage'lbearin'gs T3 's'ecured within' the chuck Qbody l, while on the 'inner side i'of leach lever are-the complementary s't'udsTwhich carry thegeii rge i bearing 1 Tithe. adjustable collet 2. 'Ihe-lockingloadisapplied tofthe ends oj'fithe -levers adjacenttd-the-colltsthroughihe' me ium ar of .links ila eani inkibeing connected .to a draw plate I6 which'.is adjustablefor tighteningror releasing thescollets.

Ihe draw .platgmay he spring Headed if sired,-soas to make the chuck slf'gr-ipping with I a predeterminedload.

M s by lop'eratiiig'the Tcollet --througli themediumsof levenandilmk mechanism pf the:eharacter described the forcle 'applied' Ito the collet for a given result is so multiplied that a firm gripping action is possible at the collets, which is further enhanced by reason of the gripping area of the collets being practically circumferential relative to the Work.

In the event of the mounting of the chuck being such that a draw tube or bar cannot be fitted, the links l5 may be operated by means of a ring l1 which encircles the housing I as shown in Figure 4 and the links 15 are withdrawn by means of the ring l8 and block I9 which is secured to the ring IT, by the stud 20.

In view of the collets 2, 3 being of semi-circular shape there is little likelihood of dirt and 3 swarf penetrating into the chuck and due to the fact that one collet is fixed relative to the chuck body no dirt can penetrate behind this jaw and the operator can be certain that the work is held in correct adjustment against the fixed collet, also there can be no lateral movement of the work as the adjustable collet or jaw moves radially. The internal gripping surfaces of the collet may be of any desired shape in formation to suit the work to be gripped in the chuck and the chuck is applicable to any machine tool where there is no hollow spindle. The chuck can be made to grip discs, threaded work, tapers and eccentrics and can be arranged for multiple gripping by either having a plurality of chucks in line or by lengthening the collets or jaws as shown in Figure 5 in which case a plurality of locking levers 8 and locking rollers 6 will be provided to bear against the adjustable collet or jaw 2 either directly or indirectly. The plurality of locking levers 8 may be arranged in 2. A collet chuck comprising in combination a pair of gripping collets or jaws, one fixed and the other adjustable relatively thereto, asystem of levers for adjusting the adjustable collet, the

levers being in two halves correspondingly i mounted on either side of the collets or jaws and a carrying a roller which bears upon the adjustable collet or jaw, and links connected with the chuck operating mechanism for actuating said levers.

3. A collet chuck comprising in combination a pair of gripping collets or jaws, one fixed and the other adjustable relatively thereto, a system of levers for adjusting the adjustable collet, the levers being in two halves each correspondingly mounted on either side of the collets or'jaws and carrying a roller which bears upon the adjustable collet or jaw, and-links connected with the chuck operating mechanism for actuating said levers, at least two pairsof operating levers being provided to operate the adjustable collets or jaws.

4. A collet chuck comprising in combination a pair of gripping collets or jaws, one fixed and "the other adjustable relatively thereto, a system 4 pair or links each connected to a draw plate for applying a locking load to the ends or the levers adjacent the collets or jaws.

5. A collet chuck comprising in combination a pair of gripping collets or jaws, one fixed and the other adjustable relatively thereto, a system of levers for adjusting the adjustable collet, the levers being in two halves correspondingly mountedon either side of the collets or jaws and carrying a roller which bears upon the adjustable collet or jaw, links connected with the chuck operating mechanism for actuating said levers, and means for operating the links while the chuck is in motion.

6. A collet chuck comprising in combination a pair of gripping collets or jaws, one fixed and the other adjustable relatively thereto, a system of levers for adjusting the adjustable collet, the levers being in two halves correspondingly mounted on either side of the collets or jaws and carrying a roller which bears upon the adjustable collet or jaw, links connected with the chuck operating mechanism for actuating said levers, and a ring encircling the housing for the collets or jaws connected by means of a block and ring to the first mentioned ring and the said links, respectively, for operating the levers adjacent the collets while the chuck is in motion.

GEO. FISHER.

' REFERENCES .CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Date 

